Long-term aerobic exercise enhances liver health: miRNA regulation and oxidative stress alleviation

This study aims to investigate the effects of long-term aerobic exercise on liver health in aging rats. As age increases, the continuous accumulation of endogenous reactive oxygen species (ROS) damages hepatocytes, leading to liver function decline and the development of diseases such as cirrhosis and liver cancer. Using an 18month-old rat model, we implemented an eight-month aerobic exercise regimen to systematically evaluate its hepatoprotective effects. The results showed that aerobic exercise effectively reduced oxidative stress and inflammation levels in liver tissue, decreased the expression of cell cycle regulator P53 and inflammatory regulator NF-kappa B protein, upregulated NRF2 protein expression, improved mitochondrial function, and inhibited the progression of ferroptosis. These beneficial effects were achieved through the upregulation of miR-21 and miR-224 expression induced by exercise. These microRNAs inhibit the translation of MAP2K3 and MAPK14, thereby suppressing the activation of the P38 MAPK pathway. We further found that inhibiting P38 MAPK can enhance cellular antioxidant and anti-inflammatory capabilities, reversing hepatocyte damage caused by hydrogen peroxide. These results demonstrate that long-term aerobic exercise can reprogram aging-related oxidative stress and metabolic pathology by regulating miRNAs and the P38 MAPK pathway, thereby helping to prevent age-related liver diseases.